Blog 9th May 2011

I have now regrettably missed blogging a few observing sessions, so rather than worry about it I’m going to pick up again and try and keep things current. The sessions not recorded in this blog (mainly because it was down due to being hacked & disabled) the observations from the missing sessions are in the sketch files.

Another development is that the mighty HST Calver is now in operation again, the latest with the historic scopes restoration will be written up shortly and added to the HST tab.

Last night’s short session is actually linked to the HST. When I acquired it, it came with a rather ugly, short 4” refractor finder with a brass Irvin R&P focuser. When we reassembled the Calver we decided to stick with just putting back the original brass finder of around 11/2” aperture as this was optically sound and pretty acceptable for aligning on bright stars.

As for the big finder it is around F5, the OG was filthy so Es took it away to clean and evaluate. I think that I remember Robert Paterson telling me that this scope had been built by Jim Muirden who was Es’s predecessor at Astronomical Equipment (AE) in the 70’s. Es quickly concluded that it was a triplet, oh good I thought, triplet to be means it is good J Not so Es informed me.

Within 24hrs Es had cleaned and tested, concluding it was OK, pretty likely of military origin, well & heavily coated and likely to be the central section of a larger lens system. He said the centre should be OK but the edge of field was likely to be rather horrid!

Last night after returning from work I did some log splitting, allotment weeding and watering, sons bike repairing and finally harmonica practice before I crudely ‘lashed’ the heavy short tube refractor on the balance point of the mount, up on the back of the 6” refractor with cable ties & making tape. I stuck a Watec camera up its backside (cover your ears Vicar!) then spent the next couple of hours trying to get the best image possible in the midst of the Virgo galaxy cloud. I fiddled, faffed, focussed and adjusted the camera settings but didn’t really get a decent image until last knockings when I actually adjusted the monitor settings! Doh, at this point it was midnight so I made a sketch of what was shown in a half degree fov around M84 & M86, considering, I was pretty pleased with the result, I would have liked a bigger fov, but I think in my ignorance this is likely as much to do with the small ½” chip as it is the scope. I managed to see 8 galaxies in the field some small ones down to mag 12 in the same fov.

When Es gets back from Norway I will discuss with him to see if this OG has any future as a widefield instrument for video observation in the observatory. 

Clear Skies, Dale